The Series 4 watch will go on sale in the US later this month costing $399, Apple announced at the product launch yesterday, calling the device “an intelligent guardian for your health”.

Advertisement

An electrocardiogram (ECG) is normally just available in hospital. Pads put onto your chest detect your heart’s electrical activity, which is shown as the well-known spiky line on a monitor.

Now Apple Watch users will be able to get an ECG at the touch of a button, by putting a finger on the “digital crown” on the watch’s side, similar to the winder on a clockwork watch. After 30 seconds, you get told if the result is normal or suggests a problem, and the recording can be shared with a doctor.

Worrying readings

The last Apple Watch could also be used to take an ECG if paired with a device called a Kardia Band, but this had to be bought separately. Having the function built into the watch will mean many more people will start regularly taking their ECG, especially if they worry about their health – and that’s where problems may start.

The feature will be useful for some people, namely those who have a condition called atrial fibrillation, where the heart beats irregularly, causing symptoms such as breathlessness, tiredness and chest pain. They sometimes need home monitoring.

But many people have an irregular heart rhythm without symptoms. They will be told by their watch to take the ECG result to a doctor. They could then get potentially risky surgery, go on unnecessary medications risking side effects such as dizziness. At the least they will be falsely alarmed.

New Scientist has asked Apple if the company has any specific measures to avoid misdiagnosis, but has yet to receive a response.

Another function, the intermittent heart rate monitor – which works though sensors built into the back of the watch face – may also have potential for false alarms. For instance, some people get panic attacks, when stress makes their heart and breathing rate race.

And there’s a third new medical feature aimed at people who have health concerns – this will call emergency services if the wearer is detected to have taken a hard fall and stays immobile for 60 seconds.

All such functions will no doubt be appreciated by people with health concerns – not to mention the worried well.